My family and I (mom, dad, 2 kids, and nanny) stayed in a 3 BR unit for the Presidents' Week holiday. The unit was spectacular -- we could have tossed a ball into the ocean from our balcony and it was a short walk to the scenic Imperial Beach pier. The location was also quite good -- it was only about 20 minutes to most of what San Diego has to offer, with the exception of the Wild Animal Park and Legoland, which are north of the city and took about 45 min - 1 hour to get to.
About Imperial Beach, there have been some comments regarding its "seediness". Here's my view: I think the area is up-and-coming, but it's certainly not La Jolla or Coronado. Then again, you're not paying for that at these prices (we got a 3 BR condo for $1200/week). Along the beach it is quite nice; as you go further from the beach there were a decent share of liquor stores and check-cashing outlets. One night there were some loud "partiers" on the beach near our unit. But overall, I felt very comfortable there with my family. The Beach Club itself was full of families.
And yes, the beach was polluted; recent heavy rains shut down all of the beaches from the Mexican border north to Coronado. It wasn't beach weather anyway so this didn't bother us; I don't know if this is always the case or not.
To wrap it up -- we would definitely go back! The Imperial Beach club offers location, value, space for a family, and amazing ocean views. It depends on what you're looking for.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC